Sequence Management; Table 5-15 Sequence Content Header - Sun Microsystems storagetek sl500 Reference Manual

Sequence Management

Sequence management deals with the actual order and transfer of frames across
Fibre Channel. The SEQ_ID and SEQ_CNT identify the order of frames for
reassembly at the responder.
Refer to the FC–PH documents for rules and guidelines pertaining to Class 2
operation.

TABLE 5-15 Sequence Content Header

Word
0
1
2
3
4
5
Sequence Open
The library considers a sequence open from the time that the first frame of the
sequence (the frame with the SOFi3 delimiter) is sent until one of the following
occurs:
An end-of-frame (EOF) delimiter is sent with the last sequence bit set
■
A LOGO is sent to, or received from, the sequence responder
■
The sequence is aborted with ABTS
■
The library as a sequence responder considers a sequence open from the time that
the first frame of the Sequence (the frame with the SOFi3 delimiter) is received
until one of the following occurs:
An end-of-frame (EOF) delimiter is sent with the last sequence bit set
■
The Sequence is aborted using ABTS
■
A LOGO is sent to, or received from, the Sequence originator
■
Sequence Identifier Usage
The sequence identifier (SEQ_ID) is a field in the frame header that sets one frame
apart from another and indicates the order in which frames occur. The following
paragraphs summarize the rules governing the reuse of SEQ_IDs.
For sequences which transfer Sequence Initiative:
An NL_Port can reuse a SEQ_ID for the same Exchange following the
■
confirmation of sequence delivery.
An NL_Port can reuse the SEQ_ID with a different exchange (to the same, or a
■
different destination NL_Port) immediately following transmission of the last
frame of the sequence, without waiting for confirmation of Sequence delivery.
96122 • Revision: F
Byte 0 Byte 1
R_CTL
CS_CTL
Type
SEQ_ID DF_CTL
OX_ID
Byte 2
Destination_ID
Source_ID
F_CTL
SEQ_CNT
RX_ID
Parameter
Chapter 5 Fibre Channel Operations 63
FC-2 Features
Byte 3